In the printing and copying fields, improvement in the working capacity of photographic plate making steps is required. Particularly in the page make-up and dot to dot work stages, an improvement in working capacity has been attempted by an operation under a brighter environment. For this purpose there have been promoted development of a silver halide photographic material for a plate making, which can be handled under an environment which could be called a bright room, and development of an exposure printer.
A silver halide photographic material for a bright room used in the present invention means a photographic material in which a light having a wavelength of 400 nm or more and containing no ultraviolet component can be used as a safelight.
For the purpose of increasing safety against the above safelight, dyes which are capable of absorbing a visible ray have been incorporated into a hydrophilic colloid layer existing farther from a support than the light-sensitive silver halide emulsion layer. When these dyes act as a filter layer, it is necessary that the layer in question is selectively colored and that the other layers are substantially not colored. If the emulsion layers are substantially colored as well, not only disadvantageous photographic effects are given to the emulsion layers but also the effect of the filter layer is reduced. In particular, there are problems such as deterioration of the spreading and chalking properties, which is specific to the dot to dot work field, reduction in tone versatility and reduction of an outline type property.
There has been hitherto known as a solution to these problems, a method of localizing a so-called acidic dye having a sulfo group and a carboxyl group in a specific layer with a mordant. Such mordants include the polymers of ethylenically unsaturated compounds having a dialkylaminoalkyl ester residue, described in British Patent 685,475; the reaction products of poly-vinylalkyl ketone and aminoguanidine described in British Patent 850,281; and vinylpyridine polymers and vinylpyridinium cationic polymers described in U.S. Pat. Nos. 2,548,564, 2,484,430, 3,148,061, and 3,756,814. In these patents, the cationic mordants having a secondary or tertiary amino group, a nitrogen-containing heterocyclic group and a quaternary cationic group thereof in the polymers are used so that the above acidic dyes can be efficiently mordanted.
In these mordands, it is often observed that the above acidic dyes diffuse to the other layers. In order to prevent the diffusion, one might consider using a lot of the mordants. However, not only can the diffusion not be completely prevented, but also the thickness of the layers into which the mordants are to be incorporated is increased, which in turn has resulted in generating new problems.
Further, in a light-sensitive material for printing plate-making, the procedure of cutting reduction, in which a reducer is used, is usually carried out. A water soluble iron complex is contained as a reduction cutting agent in the reducer, and the use of the above cationic mordants generates the disadvantage that they electrostatistically combine with this iron complex to yield yellow stain by the iron complex.
Further, the other known means for fixing the dyes in a specific layer of a photographic material is to add the dyes as a dispersed solid as disclosed in JP-A-56-12639 (the term "JP-A" as used herein means an unexamined published Japanese patent application), JP-A-55-155350, JP-A-55-155351, JP-A-52-92716, JP-A-59-193447, JP-A-61-198148, JP-A-63-197943, JP-A-63-27838, and JP-A-64-40827, European Patent 0015601B1 and European Patent 0276566A1, and International Patent WO 88/04794. However, it is not known how to combine silver halide ultra fine grain therewith to increase Dm and satisfy the properties which are specific to the dot to dot work field. Also, it has been impossible to completely attain the tone reproducibility required for a dot to dot work light-sensitive material.